petro (aspirin free) is a combination of drotaverine HCI which is a very safe spasmolytic with acetaminophen which is a well known analgesic and an£Ipyretic “gent. It Is used safely with patients allergic to aspirin (e.g. in patients with asthma, chronic urtiCaria), in gastrolntestinal diseases (e.g In ulcers, gastritis), in hemophlIla and bleeding ulcers. caffeine which is a methylxanthlne frequently included In preparations containing acetamInophen.
– Drotaverlne HCI affects directly the smooth muscle. It acts by’ elevation of cAMP level through phosphodiesterase inhibition, It normalises the smooth muscle tone bringing the hypertonic state to a normotonic state. Drotaverine HCI is adsorbed onto the surface of the smooth muscle cells and thereby, modifies their membrane potential and permeability.
Acting on the smooth muscles of coronaries and cerebral blood vessels, -it is effective In increasing blood fiow to the coronaries and cerebral blood vessels, hence, it is used in the treatment and prophylaxis ~nst coronary artery spasm and in headache of vascular ongm.
Drotaverine HCI relieves or prevents the development of spasms of the various smooth muscle organs, regardless of their function. Drotaverlne HCI is a spasmolyUc agent stronger than papaverine and ethaverine without their h) ‘potensive effect. It has no anticholinergic effect, hence no SIde effects such as drowsinesspreparations such-as parasympatholyUcs and analgesics.
– Acetaminophen has analqeslc and antipyretic properties. It is as potent as aspirin in inhibItIng prostaglandin synthesis in the CNS with minimal effect in the periphery which may account for its lack of anti-inflammatory effect .
– caffeine is central nervous system stimulant It inhibits the enzyme phosphodiesterase. It is frequently included in analgesic preparation as it is known that the adjuvant use of caffeine can increase analgesic .activity. It has also a peripheral vasodilator effect which adds to the spasmolytic effect of drotaverine HCI in treatment of spastic vascular condltlons.

Indications:

It is indIcated in all conditions associated with pain, fever and spasms as in:
1- Spasmodic dysmenorrhoea, acute adenitis, in pain following gynaecological operations.
2- Renal colic as in nephrolithiasis, pyelitis, cystitis, prostatitis …. etc .
3- Biliary colics such as cholelithiasis, cholecystitis … etc.
4- Treatment of headache of different types especially headache of vascuiar ori!lin.
5- As adjuvant In treatment of peptic, duodenal ulcers, gastritis and vasospastic angina.

pharmacokinetics:

Drotaverine HCl’s absorption is extremely rapid Tl/2abs. is 12 minutes. Its clinical effect lasts for 4 hours, this fact strongly suggests that the metabolites possess pharmacological action even stronger than the original drotaverine (Z Vargay). ‘the plasma levels reach their peak between 45 and 60 minutes indicating rapid absorption. The half life of drotaverine HCI is 16 hours regardless the route of
administration. According to the urinary and faecal elimination data, the elimination of drotaverine is practically compieted within 72 hours.
Acetaminophen is readily absorbed from the gastrointestinal tract with peak plasma concentration occurlng about I 0 to 60 minutes alter oral administration. It is distributed into most bad)’ tissues. It is metabolise<!.R,redominantly in the liver and excreted In the urine conjugates. The elimination caffeine is absorbed readily alter oral administration and is widely distributed throughout the body. It crosses the placenta. It is metabolised almost completely in the liver and is excreted in the
urine. ;liminatlon half- life is 3 to 6 hours in adults.
Petro is prepared in a very special way that allows its rapid absorption to reach the optimum plasma level in a very short time as drotaverine normalises the smooth muscle fibres tone of blood vessel walls and GIT even in cases of stomach and intestinal spasms, that usually accompany the higb fever. This fact facilitates
the penetration of acetaminophen and Caffeine to the CNS together with drotaverine. where they control directly the heat regulating and pain centres.